Page 344 of he manual will tell you the std spec and optionals.
You can safely go from a 52 to a 38 mm offset on a 17x7.5 wheel
On how 18 and 19 you will have to compensate for the width of the tire and wheel so try to stick to 38 to 45 mm on the offset
The CLA 45 will not accept 17" wheels, the brake package is too big
If you have to go for a 35mm offset just keep in mind that the tire will show about 1/8 of rubber and could run a bit of interference on a severe rebound situation such as hitting a speed bump at moderate speed.